Williams makes an important point – that how you want to live can be suffocated by how others assume you should live. But it is unfair to suggest that sharing is crowding out individual choice. The truth is the other way round.

Williams focuses on the part of our report that says the cost of living alone is £3,500 a year – inflation, council tax, etc, all make it more expensive to live alone than in a couple, family or group. Williams says: "A story like this isn't for the purposes of information; its purpose is to concatenate behaviour that runs against the norm with negative consequences." Basically, she thinks it's a story about why single life is bad and nuclear family life is good. That was absolutely not our intention in producing the report. The Great Sharing Economy was produced for Co-operatives Fortnight, an annual celebration of co-operation with a theme, this year, of yours to share.

As the UK body that campaigns for co-operation, we know that people can do better by sharing, whether that's cutting costs and overheads by bulk-buying, or cutting carbon emissions by car-sharing.

We do think that it's better for people to share – in their street, in workplaces and at home. After all, what is the social and environmental cost of landscapes carved up by roads used by cars with single-occupancy drivers; of houses packed with possessions that we keep to ourselves? But we would never say that sharing is about family life, or that there's only one way of living.

Williams asks: "Why is living communally never considered, outside education, nursing homes and sitcoms? ... Those of us who'd prefer to live in gangs have instead paired off into twos, lemming-like in our conformity, but in the outcomes, in our small, traditional households, un-lemminged."

Co-operatives have pioneered more collective ways of organising and living, sometimes for people to live in gangs, often for people to organise their home and work life collectively. There are over 60,000 people in the UK living in 650 housing co-operatives. These are groups of people – ranging in size from five up to thousands – who run their homes, flats and estates together. They have realised that you can do your own thing and still live with other people. More broadly, there are over 5,000 co-operative enterprises, where everyday people have come together to run an organisation or business as a team. Employees, customers, local communities – all are working together and creating a great sharing economy.

Williams is absolutely right – there is no doubt that living alone often goes against the norm. As an organisation that campaigns for co-operatives – which constantly defy conventions – we know better than most what it is to go against the norm.